大黄鱼网箱养殖水体的细菌群落结构

Bacterial composition in large yellow croaker(Larimichthys crocea) culture water

以16S r DNA为分子标记,通过构建克隆文库、限制性片段长度多态性(Restriction Fragment Length Polymorphism,RFLP)分析等技术手段,研究大黄鱼(Larimichthys crocea)网箱养殖水体中细菌的群落结构。样品采自福建省宁德市三都湾富发养殖基地。随机选取5个不同养殖网箱水样混合,取3 L混合水样过滤富集细菌后提取总DNA,用细菌通用引物27F和1 492R扩增其16S r RNA基因,构建克隆文库。从文库中随机挑选154个克隆子进行分析,得到137个阳性克隆,92种RFLP带型。对部分代表性克隆子进行测序的结果表明,大黄鱼养殖水体中细菌多样性非常丰富。序列分析结果显示,γ-变形菌纲的假交替单胞菌属(Pseudoalteromonas)细菌为最优势菌(占γ-变形菌纲克隆子数的31.2%),海源菌属(Idiomarina)次之(占γ-变形菌纲克隆子数的15.1%)。此外还存在6.6%的厚壁菌门(Firmicutes)、5.9%的拟杆菌门(Bacteroidetes)、各0.7%的浮霉状菌门(Planctomycetes)、绿屈挠菌门(Chloroflexi)、绿菌门(Chlorobi)细菌和OP11类群。本研究结果阐明了网箱养殖大黄鱼水体细菌的群落结构,为大黄鱼养殖区病害防治、环境监测以及探讨大黄鱼健康养殖与养殖水体细菌间的关系奠定了基础。

The large yellow croaker （Larimichthys crocea） is one of China’s major economic sea fish because of its high commercial value. In recent years, as the scale of aquaculture has expanded and the environment has deteri-orated, large yellow croaker diseases have occurred frequently. Healthy culture of large yellow croaker is closely linked to the bacteria in aquaculture environments because bacteria degrade organic pollutants and play important roles in material transformation and energy flow in mariculture systems. Therefore, it is important to monitor bac-terial composition in aquaculture environments to ensure sustainable development of healthy large yellow croaker. In this study, 16S rDNA was used as a molecular marker to explore bacterial community structure in large yellow croaker cage culture water by clone library construction, Restriction Fragment Length Polymorphism （RFLP） analysis, and sequence analysis. Samples were collected from Sandu Bay Fufa aquaculture base in Ningde, Fujian province. Water samples from 5 cultivation cages were mixed and 3 liters of this mixed water were filtered to enrich the bacteria. Total DNA was extracted and used for PCR amplification of 16S rRNA genes using the bac-terial universal primers 27F and 1 492R, and then the 16S rDNA clone library was constructed. From the clone library of the water sample, 154 clones were picked randomly. A total of 137 positive clones and 92 RFLP patterns were obtained from the clone library. Representative clones were sequenced, and the results revealed a high bac-terial genetic diversity. Pseudoalteromonas （15.1%γ-Proteobacteria） ofγ-Proteobacteria was the most dominant group, and Idiomarina （31.2%γ-Proteobacteria） was the second dominant group. In addition, Firmicutes （6.6%）, Bacteroidetes （5.9%）, Planctomycetes （0.7%）, Chloroflexi （0.7%）, Chlorobi and OP11 （0.7%） were also present. The results provide a foundation for investigating the relationship between healthy aquaculture of L.crocea and the bacteria in mariculture water.